ᐅ Exterior walls made of 24 cm hollow clay bricks: should I use external thermal insulation composite systems (ETICS) or Poroton T7 blocks?

No idea who changed the title. My original heading is:
Exterior walls built with 24cm (9.5 inches) hollow bricks with external thermal insulation composite system (ETICS) or Poroton T7 42.5cm (17 inches)?

I have the Unipor W08 Plan with 36.5cm (about 14.4 inches) thickness, which are basically the same as the T8 Poroton. So far, I am very satisfied—there are no soundproofing issues, although most noise comes through the windows anyway. Inside the house, it is not overly noisy. The thick concrete ceiling provides good sound insulation between the floors.

If in doubt, I would have chosen at most 42.5cm (about 16.7 inches) for slightly better insulation, but that is probably money wasted.

Bookstar schrieb:

If you’re on the phone on the ground floor, you can hear it on the upper floor.

Well, this really can’t be blamed on the bricks of the exterior wall when you have a solid reinforced concrete slab between the floors, with the brick wall completely interrupted all around. How could anything possibly transfer through the exterior wall then?

Or do you only have a cheap timber floor/ceiling assembly?

Ötzi Ötztaler schrieb:

So, this really can’t be blamed on the exterior wall bricks, especially if there’s a solid reinforced concrete floor slab between the levels, where the brick wall is completely interrupted all around. How could anything then be transmitted through the exterior wall?

Or do you only have a cheap wooden intermediate floor?

Of course, it’s a solid concrete floor slab. The sound still passes through. I have checked this in several houses. And in apartment buildings, you also have concrete floor slabs. Try it yourself. Put your ear on the brick wall of the upper floor, and you hear everything from the ground floor. It is purely due to the poor quality of the bricks. Or try knocking on the wall; it’s a hollow body.

So, a hollow brick also has continuous perforations like an unfilled Poroton block. Sound should then be transferable between floors in this case as well. The only solution would be filled Poroton or a concrete wall with ETICS (External Thermal Insulation Composite System). That can’t be right, can it?

Well, or calcium silicate bricks. Most people simply don’t mind that. Also, the concrete ceiling doesn’t continue through, since you need thermal insulation at the end face. That alone creates a significant thermal bridge. Nowadays, gluing the bricks makes the effect even worse.